The present invention relates generally to the field of pulse detonation engines. More particularly, the present invention relates to a twin-tube, rotary inlet valve, pulse detonation engine propulsion pod having a shared, two-dimensional wedge nozzle with thrust vectoring capability.
A pulse detonation engine utilizes a series of repetitive detonations within a detonation chamber to produce a high pressure exhaust. The detonation of gaseous fuel in the detonation chamber causes a pulse detonation wave to propagate at supersonic speeds. The detonation wave compresses the fluid in the detonation chamber, thereby increasing its pressure, density, and temperature. As the detonation wave passes out of the open, downstream end of the chamber, the supersonic flow expands to ambient pressure, and the pulse detonation engine experiences thrust.
A pulse detonation engine is distinct from a pulse jet engine which utilizes a deflagration combustion process. Deflagration waves are subsonic in contrast to the supersonic speeds of detonation waves.
A pulse detonation engine could be employed to power missiles, rockets, or other subsonic and supersonic vehicles. The vectoring of these flight vehicles in the pitch and yaw directions generally requires the use of external control surfaces; however, these types of control surfaces add weight to the vehicle and provide relatively slow response. Thus, for such applications, it is advantageous to integrate the pulse detonation engine into an aerodynamically efficient, thrust-vectored propulsion pod. The present invention satisfies this need in a novel and unobvious way.
One aspect of the invention described herein is the integration of a twin-tube, rotary inlet valve, pulse detonation engine into an aerodynamically efficient propulsion pod. The present invention further provides a simple, low-cost combustion case cooling system that includes flowing a portion of the inlet air into an outer annular bypass channel that contains means for cooling the detonation tubes. The cooling means may be a plurality of thin radial cooling fins, honeycomb passages, or pin fins that act as a heat sink for cooling the outer cases of the detonation tubes.
Another aspect of the invention is the integration of the exhaust nozzle with the detonation tubes. One embodiment of the present invention includes a shared, two-dimensional, low aspect ratio wedge nozzle in which each side of the wedge is transitioned into the discharge end of the detonation tubes. The nozzle design results in a quasi-separate exhaust flow path with two separate nozzle throat areas, one for each detonation tube. Pitch vectoring of the exhaust can is provided by mechanically actuating a center wedge member. In another embodiment, a pair of triangular hinged flaps are integrated into the side walls of the nozzle to provide a degree of yaw vectoring.
One object of the present invention is to provide a unique pulse detonation bypass engine propulsion pod.
Related objects and advantages of the present invention will be apparent from the following description.